Isolated patent ductus arteriosus (PDA) is a congenital cardiac defect diagnosed in over 13,000 infants and several thousand children in the US annually. While the circulatory and infectious consequences of PDA may be prevented by surgery, implantation of the Rashkind double occluder is a recently developed alternative. If successful, this cardiac catheterization procedure avoids the risks of open-chest surgery, while reducing costs and convalescent time. Occluder use has serious potential complications and appears to be less successful than conventional surgery. However, it may be repeated or followed by surgery if necessary. There are limited outcome data available on the 300 occluder placements already attempted and no published information on comparable surgical controls or on costs for either procedure. In the proposed review of records from sixteen major US and Canadian centers, success and complication rates and resources used to treat approximately 250 PDA occluder placements attempted between 1981 and 1987 are being compared to outcomes of roughly 750 surgical closures performed between 1980 and 1987 in similar patients. Among occluder patients, factors associated with successful closure or complications will be identified. A cost-effectiveness analysis will consider which treatment approach should provide greater clinical benefit for a given monetary expenditure. A decision analysis will model the potential impact on therapy choice of hypothetical changes in success and complication rates, and other factors. FDA review of the application for release of the occluder is imminent, but will occur with very limited data. The proposed investigation may provide the only systematic comparison upon which parents, clinicians and policy makers can base decisions about occluder use, should be application be either approved or deferred for future reconsideration. Data from this retrospective study will be useful for planning a future randomized clinical trial and should also facilitate future design of a prospective study of occluder use in premature infants and other patients. It will also provide general information of incidence and costs of PDA closure. The project should stimulate interst in performing other systematic studies of interventions in pediatric cardiology. Through the use of specific data collection and analysis procedures designed to minimize study bias, this investigation should contribute to the methodology of clinical and cost effectiveness evaluations using medical records and other existing data.